Note: Descriptions are shown in the official language in which they were submitted.
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USE OF NK-1 RECEPTOR ANTAGONISTS FOR TREATING
BIPOLAR DISORDERS
This invention relates to the treatment or prevention of bipolar
disorders by the administration of a specific class of NK-1 receptor
antagonists.
Bipolar disorder, otherwise known as manic depressive disorder or
bipolar affective disorder, is characterised by alternating conditions of
mania and depression. The nature of the clinical course of the bipolar
disorder may give rise to a diagnosis of bipolar I disorder, bipolar II
disorder or cyclothymic disorder. Bipolar I disorder is generally
considered to be the most severe, being an alternation of major depressive
episodes and manic episodes. Bipolar II disorder refers to an alternation
of major depressive episodes and hypomanic episodes, whilst cyclothymic
disorder refers to an alternation of depressive symptoms and hypomanic
symptoms.
Treatment regimens commonly include the use of tricyclic
antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), some
psychotropic drugs, lithium carbonate, and electroconvulsive therapy
(ECT) (see R. J. Baldessarini in Goodman & Gilman's The
Pharmdcologicc~l Bacsis of Therapeutics, 9th Edition, Chapter 19, McGraw-
Hill, 1996 for a review}. More recently, new classes of antidepressant
drugs are being developed including selective serotonin reuptake
inhibitors (SSRIs), specific monoamine reuptake inhibitors and 5-HTiA
receptor agonists and antagonists.
The most established drug treatment for the management of
depressive episodes are the tricyclic antidepressants. For instance,
depressed patients with prominent sleep disturbance and anxiety may be
treated with a sedating tricyclic antidepressant such as amitriptyline; for
other patients, less sedating compounds such as imipramine or
desipramine can be used. As well as inhibiting the uptake of
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2
noradrenaline and 5-hydroxytriptamine, tricyclic antidepressants also
possess antagonist properties at a variety of neurotransmitter receptors,
including muscarinic cholinergic receptors, al-adrenoceptors and
H1-histamine receptors. These receptor antagonist effects account for
much of the side-effect profile of the tricyclic antidepressants, and in
particular, their anticholinergic side-effects which are particularly
troublesome in patients with prostatic enlargement or glaucoma. Other
side-effects include dry mouth, tachycardia, difficulty in visual
accommodation, constipation, urinary retention, sexual dysfunction,
cognitive impairment, postural hypotension, and weight gain.
Monoamine oxidase inhibitors are generally prescribed for patients
who have failed to respond to tricyclic antidepressants or electroconvulsive
therapy. As with tricyclic antidepressants, there are a number of side-
effects associated with the use of MAOIs including dizziness, muscular
twitching, insomnia, confusion, mania, tachycardia, postural hypotension,
hypertension, dry mouth, blurred vision, impotence, peripheral oedema,
hepatocellular, damage and leucopenia.
Of the new classes of antidepressant, selective serotonin reuptake
inhibitors are increasingly prescribed, particularly in patients where the
use of tricyclic antidepressants is contraindicated because of their
anticholinergic and cardiotoxic effects. SSRIs such as fluoxetine,
fluvoxamine, sertraline and paroxetine are generally non-sedating.
Furthermore, SSRIs do not stimulate appetite and may therefore be
appropriate in patients in whom weight gain would be undesirable.
However, SSRIs are not without their own side-effects, including nausea,
diarrhoea, dry mouth, reduced appetite, dyspepsia, vomiting, headache,
nervousness, insomnia, anxiety, tremour) dizziness, fatigue, decreased
libido, pharyngitis, dyspnoea, skin rash and sexual dysfunction.
Treatment of manic episodes is with drugs and psychological
management. Typically, drugs such as haloperidol or chlorpromazine may
be used to control symptoms. After more than one episode of mania,
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3
lithium carbonate is often prescribed. Drugs such as haloperidol and
chlorpromazine are typically associated with a number of side-effects,
including extrapyramidal symptoms, acute dystonias or dyskinesias,
akathesia, tremour, tachycardia, drowsiness, confusion, postural
hypotension, blurring of vision, precipitation of glaucoma, dry mouth,
constipation, urinary hesitance and impaired sexual function. The
therapeutic index of lithium is low and close control of plasma
concentrations is required for its safe clinical application. Side-effects of
lithium include tremour, nausea, diarrhoea, thirst and polyuria.
Whatever drug is used, there is a delay of usually two, three or even
four weeks before a therapeutic effect is observed. This period of delay
may be particularly difficult for a patient suffering from a bipolar disorder.
Neurokinin 1 (NK-1; substance P) receptor antagonists are being
developed for the treatment of a number of physiological disorders
associated with an excess or imbalance of tachykinins, and in particular
substance P. Examples of conditions in which substance P has been
implicated include disorders of the central nervous system such as anxiety,
depression and psychosis (see, for instance, International {PCT) patent
specification Nos. WO 95/16679, WO 95//8124 and WO 95/23798).
More recently, International (PCT) patent specification No. WO
96/24353 (published 15th August 1996) suggests that a more efficacious
and safe treatment of psychiatric disorders would be achieved using a
combination of a tachykinin antagonist and a serotonin agonist or
selective serotonin reuptake inhibitor (SSRI). However, such as regimen
would not be free of side-effects due to the serotonin agonist or SSRI.
NK-1 receptor antagonists are described in published European
Patent Specification Nos. 0 360 390, 0 394 989, 0 429 366, 0 443 I32,
0 482 539, 0 512 901, 0 512 902, 0 514 273, 0 514 275, 0 517 589,
0 520 555, 0 522 808, 0 528 495, 0 532 456, 0 533 280, 0 536 817,
0 545 478, 0 577 394, 0 590 152, 0 599 538) 0 610 793, 0 634 402,
0 686 629, 0 693 489, 0 694 535, 0 699 655, 0 699 674, 0 707 006,
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0 708 101, 0 ?14 891, 0 723 959, 0 733 632 and 0 7?6 893; and in
Inter national Patent Specification Nos. 90/05525, 90/05729, 91/09844,
91/18899, 92/01688, 92/06079, 92/12151, 92/15585, 92/17449, 92/20661,
92/20676, 92/21677, 93/00330, 93100331, 93/01159, 93/01165, 93/01169,
93/01170, 93/06099, 93/09116, 93/10073, 93/14113, 93118023, 93119064,
93/21155, 9321181, 93/23380, 93/24465, 94/01402, 94/02461, 94/03429,
94/03445, 94/04494, 94/04496, 94/05625, 94/07843, 94/10165, 94/10167,
94/10168, 94/10170, 94/11368, 94/13639, 94/13663, 94/14767, 94/15903)
94119320, 94/19323, 94/20500, 94/26735, 94/26740, 94/29309, 95/02595,
95/04040, 95104042, 95/06645, 95107886, 95/07908, 95/08549, 95/11880,
95/14017, 95/15311, 95/16679, 95/17382, 95/18124, 95/18129, 95/19344,
95120575, 95/21819, 96/22525, 95123798, 95/26338, 95/28418, 95/30674,
95/30687, 96/05193, 96105203, 96/06094, 96/07649, 96/10562, 96/16939,
96/18643, 96/20197, 96/2166/) 96/29304, 96129317, 96/29326, 96/29328,
96/31214, 96/32385, 96/37489, 97/01553, 97/01554, 97/03066, 97/08144,
97/14671; '97/17362; 97/18206, 97/19084, 97/19942 and 97/21702; and in
British Patent Specification Nos. 2 266 529, 2 268 931, 2 269 170,
2 269 590, 2 271 ?74, 2 292 144, 2 293 168, 2 293 169, and 2 302 689.
In view of the short-comings of existing therapy, there is a need for
new, safe and effective treatment for bipolar disorders.
The present invention provides the use of a CNS penetrant NK-1
receptor antagonist in an oral, once-a-day medicament for the treatment of
bipolar disorder. The compounds of this class advantageously exhibit a
rapid onset of action and a reduced side-effect profile when compared
against conventional mood-altering agents.
In particular, the present invention provides a means for the
identification of NK-1 receptor antagonists which would be effective in an
oral once-a-day medicament for the treatment of bipolar disorders. The
aforementioned patent specifications which describe NK-1 receptor
antagonists provide no reliable method for the identification of such
compounds.
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The exceptional pharmacology of the class of NK-1 receptor
antagonists of use in the present invention enables the treatment of
bipolar disorders, without the need for concomitant therapy using tricyclic
antidepressants or monoamine oxidase inhibitors or, in particular, without
the need for concomitant use of a serotonin agonist or an SSRI.
Furthermore, the exceptional pharmacology of the class of NK-I
receptor antagonists of use in the present invention results in a rapid
onset of action.
The present invention accordingly provides the use of an orally
active, long acting, CNS-penetrant NK-1 receptor antagonist (as
hereinafter defined) for the manufacture of a medicament adapted for oral
administration for the treatment or prevention of bipolar disorder without
concomitant therapy with other antidepressant or anti-anxiety agents.
The present invention also provides a method for the treatment or
prevention of bipolar disorder without concomitant therapy with othex
antidepressant or anti-anxiety agents, which method comprises the oral
administration to a patient in need of such treatment of an effective
amount of an orally active, long acting, CNS-penetrant NK-1 receptor
antagonist (as hereinafter defined).
In a further aspect of the present invention, there is provided an
oral pharmaceutical composition for the treatment of bipolar disorder
which comprises essentially an orally active, long acting, CNS-penetrant
NK-1 receptor antagonist (as hereinafter defined), together with a
pharmaceutically acceptable carrier or excipient.
There exists a patient population in whom bipolar disorder is
inadequately treated with lithium. Furthermore, some patients may be
adversely affected by the side-effects of lithium.
The present invention accordingly provides the use of an orally
active, long acting, CNS-penetrant NK-1 receptor antagonist for the
manufacture of a medicament adapted for oral administration for the
treatment or prevention of bipolar disorder, without concomitant therapy
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with other antidepressant or anti-anxiety agents, in a patient who is non-
responsive to lithium or for whom lithium is contraindicated.
The present invention also provides a method for the treatment or
prevention of bipolar disorder, without concomitant therapy with other
antidepressant or anti-anxiety agents, in a patient who is non-responsive
to lithium or for whom lithium is contraindicated, which method comprises
or al administration to the patient in need of such treatment of an effective
amount of an orally active, long acting) CNS-penetrant NK-1 receptor
antagonist.
Furthermore, there exists a patient population in whom bipolar
disorder is inadequately treated with heterocyclic antidepressants (TCAs,
tetracyclics, and the like), SSRIs, mixed serotonin and norepinephrine
reuptake inhibitors, dopamine reuptake inhibitors or MAOIs.
Furthermore, some patients may be adversely affected by the side-effects
of antidepressants.
The present invention accordingly provides the use of an orally
active, long acting, CNS-penetrant NK-1 receptor antagonist for the
manufacture of a medicament adapted for oral administration for the
treatment or prevention of bipolar disorder, without concomitant therapy
with other antidepressant or anti-anxiety agents, in a patient who is non-
responsive to heterocyclic antidepressants (TCAs, tetracyclics, and the
like), SSRIs, mixed serotonin and norepinephrine reuptake inhibitors,
dopamine reuptake inhibitors or MAOIs, or for whom heterocyclic
antidepressants (TCAs, tetracyclics, and the like), SSRIs, mixed serotonin
and norepinephrine reuptake inhibitors, dopamine reuptake inhibitors or
MAOIs are contraindicated.
The present invention also provides a method for the treatment or
prevention of bipolar disorder, without concomitant therapy with other
antidepressant or anti-anxiety agents, in a patient who is non-responsive
to heterocyclic antidepressants (TCAs, tetracyclics, and the like), SSRIs,
mixed serotonin and norepinephrine reuptake inhibitors, dopamine
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reuptake inhibitors or MAOIs, or for whom heterocyclic antidepressants
(TC As, tetracyclics, and the like), SSRIs, mixed serotonin and
norepinephrine reuptake inhibitors, dopamine reuptake inhibitors or
MAOIs are contraindicated, which method comprises oral administration
to the patient in need of such treatment of an effective amount of an orally
active, long acting) CNS-penetrant NK-1 receptor antagonist.
As used herein, the term "non-responsive" in relation to major
depressive disorder means patients who have not had a reasonable clinical
response {e.g. a 50% reduction in Hamilton Depression Scale (HAM-D)
from a patient's baseline score after treatment with one or more clinical
courses of conventional antidepressants).
As used herein, the term "bipolar disorder" includes bipolar I
disorder, bipolar II disorder, cyclothymic disorder and bipolar disorder not
otherwise specified. Bipolar I disorder is an alternation of major
depressive episodes and manic episodes. Bipolar II disorder refers to an
alternation-of major depressive episodes and hypomanic episodes.
Cyclothymic disorder refers to an alternation of depressive symptoms and
hypomanic symptoms.
A "major depressive episode" is defined as at least two weeks of
depressed mood or loss of interest, which may be accompanied by other
symptoms of depression. The symptoms must persist for most of the day
(i.e. for at least two thirds of the patients' waking hours), nearly every day
{i.e. for at least ten out of fourteen days) for at least two consecutive
weeks. A "depressed mood" is often described by.the patient as feeling sad,
hopeless, helpless or worthless. The patient may also appear sad to an
observer, for example, through facial expression, posture, voice and
fearfulness. In children and adolescents, the mood may be irritable. A
"loss of interest" is often described by the patient as feeling less
interested
in hobbies or not feeling any enjoyment in activities that were previously
considered to be pleasurable.
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A major depressive episode may be accompanied by other symptoms
of depression including significant weight loss when not dieting or weight
gain (e.g. a change of more than 5% body weight in one month), or
decrease or increase in appetite; insomnia or hypersomnia; psychomotor
agitation or retardation; fatigue or loss of energy; feelings of worthlessness
or excessive or inappropriate guilt; diminished ability to think or
concentrate; or indecisiveness; and recurrent thoughts of death, recurrent
suicidal ideation with or without a specific plan, or a suicide attempt.
A "manic episode" is defined by a distinct period during which there
is an abnormally and persistently elevated, expansive, or irritable mood.
This period of abnormal mood must last at least 1 week (or less if
hospitalization is required). The mood disturbance must be accompanied
by at least three additional symptoms from a list that includes inflated
self esteem or grandiosity, decreased need for sleep, pressure of speech,
flight of ideas, distractibility, increased involvement in goal-directed
activities or psychomotor agitation, and excessive involvement in
pleasurable activities with a high potential of painful consequences. If the
mood is irritable (rather than elevated or expansive), at least four of the
above symptoms must be present. The disturbance must be sufficiently
severe to cause marked impairment in social or occupational functioning
or to require hospitalization, or it is characterised by the presence of
psychotic features.
A "hypomanic episode" is less severe than a manic episode. The
symptoms of a hypomanic episode are generally the same as those which
define a manic episode, except that delusions and hallucinations are not
present and the episode is not severe enough to cause marked impairment
of social and occupational functioning or to require hospitalisation of the
individual.
As used herein, the term "treatment" refers both to the treatment
and to the prevention or prophylactic therapy of the aforementioned
conditions.
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Preferred NK-1 receptor antagonists for use in the present
invention are selected from the classes of compounds described in
European Patent Specification No. 0 577 394, and International Patent
Specification Nos. 95/08549, 95/18124, 95/23798 and 96105181, and
International Patent Application No. PCT/GB97/OI630. The preparation
of such compounds is fully described in the aforementioned publications.
Particularly preferred NK-1 receptor antagonists of use in the
present invention include:
2-(S)-(3,5-bis(trifluoromethyl)benzyloxy)-3(S)-(4-fluorophenyl)-4-(3-(5-oxo-
1H,4H-1,2,4-triazolo)methyl)morpholine;
2-(R)-(1-(R)-(3, 5-bis(trifluoromethyl)phenyl)ethoxy)-4-(3-(5-oxo-1H,4H-
1,2,4-triazolo)methyl)-3-(S)-phenyl-morpholine;
2-(S)-(3,5-bis(trifluoromethyl)benzyloxy)-4-{3-(5-oxo-1H,4H-1,2,4-
triazolo)methyl)-3-(S)-phenyl-morpholine;
2-(R)-(1-(R}-(3,5-bis(trifluoromethyl)phenyl)ethoxy}-3-(S)-(4-fluorophenyl)-
4-(3=(5-oxo=1H,4H=I;2;4-triazoio}methyl)morphoiine;-
2-(R)-(I-(R)-(3, 5-bis(trifluoromethyl)phenyl)ethoXy)-4-(5-(N, N-
dimethylamino)methyl-1,2, 3-triazol-4-yl)methyl-3-(S)-phenylmorpholine;
2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-4-(5-{N,N-
dimethylamino)methyl-1,2,3-triazol-4-yl)methyl-3-(S)-(4-
fluorophenyl)morpholine;
2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-fluorophenyl)-
4-(3-(4-monophosphoryl-5-oxo-1H-1,2,4-triazolo)methyl)morpholine;
2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-ffuorophenyl)-
4-(3-(1-monophosphoryl-5-oxo-1H-1,2,4-triazolo)methyl)morpholine;
2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-fluorophenyl)-
4-(3-(2-monophosphoryl-5-oxo-1H-1, 2, 4-triazolo)methyl)morp holine;
2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-fluorophenyl)-
4-(3-(5-oxyphosphoryl-1H-1,2,4-triazolo)methyl)morpholine;
2-(S)-(1-{R)-(3,5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-fluorophenyl)
4-(3-(1-monophosphoryl-5-oxo-4H-1,2,4-triazolo)methyl)morpholine;
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2-(R)-(1-(R)-(3,5-bis(triffuoromethyl)phenyl)ethoxy)-4-(4-N,N- .
dimethylaminobut-2-yn-yl)-3-(S)-(4-ffuorophenyl)morpholine;
(3S, 5R, 6S)-3-[2-cyclopropoxy-5-(triffuoromethoxy)phenyl]-6-phenyl-1-oxa-
7-aza-spiro[4.5]decane;
(3R,5R,6S)-3-[2-cyclopropoxy-5-(triffuoromethoxy)phenyl]-6-phenyl-1-oxa-
7-aza-spiro[4.5]decane;
or a pharmaceutically acceptable salt thereof.
Full descriptions of the preparation of the NK-1 receptor
antagonists which may be employed in the present invention may be found
in the references cited herein.
Suitable pharmaceutically acceptable salts of the NK-1 receptor
antagonists of use in the present invention include acid addition salts .
which may, for example, be formed by mixing a solution of the compound
with a solution of a pharmaceutically acceptable non-toxic acid such as
hydrochloric acid, fumaric acid, malefic acid, succinic acid, acetic acid,
citric
acid,' tartaric acid, carbonic-acid; p-hosphoric acid or sulphuric acid. Salts
of amine groups may also comprise the quaternary ammonium salts in
which the amino nitrogen atom carries an alkyl, alkenyl, alkynyl or
aralkyl group. Where the compound carries an acidic group, for example a
carboxylic acid group, the present invention also contemplates salts
thereof, preferably non-toxic pharmaceutically acceptable salts thereof)
such as the sodium, potassium and calcium salts thereof.
Preferably the compositions containing an NK-1 receptor antagonist
of use according to the present invention are in unit dosage forms such as
tablets, pills, capsules, wafers and the like. Additionally, the NK-1
receptor antagonists of use according to the present invention may be
presented as granules or powders for extemporaneous formulation as
volume defined solutions or suspensions. Alternatively, the NK-1 receptor
antagonists of use according to the present invention may be presented in
ready-prepared volume defined solutions or suspensions. Preferred forms
are tablets and capsules.
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For preparing solid compositions such as tablets, the principal
active ingredient is mixed with a pharmaceutical carrier, e.g. conventional
tableting ingredients such as corn starch, lactose, sucrose, sorbitol, talc,
stearic acid, magnesium stearate, dicalcium phosphate or gums, and other
pharmaceutical diluents, e.g. water, to form a solid preformulation
composition containing a homogeneous mixture of a compound of the
present invention, or a non-toxic pharmaceutically acceptable salt thereof.
When referring to these preformulation compositions as homogeneous, it is
meant that the active ingredient is dispersed evenly throughout the
composition so that the composition may be readily subdivided into
equally effective unit dosage forms such as tablets, pills and capsules.
This solid preformulation composition is then subdivided into unit dosage
forms of the type described above containing from 0.1 to about 500 mg of
the active ingredient of the present invention. The tablets or pills of the
novel composition can be coated or otherwise compounded to provide a
dosage form affording the advantage of prolonged action. For example, the
tablet or pill can comprise an inner dosage and an outer dosage
component, the latter being in the form of an envelope over the former.
The two components can be separated by an enteric layer which serves to
resist disintegration in the stomach and permits the inner component to
pass intact into the duodenum or to be delayed in release. A variety of
materials can be used for such enteric layers or coatings, such materials
including a number of polymeric acids and mixtures of polymeric acids
with such materials as shellac, cetyl alcohol and cellulose acetate.
The liquid forms in which the novel compositions of the present
invention may be incorporated for administration orally include aqueous
solutions, suitably flavoured syrups, aqueous or oil suspensions, and
flavoured emulsions with edible oils such as cottonseed oil, sesame oil,
coconut oil, peanut oil or soybean oil, as well as elixirs and similar
pharmaceutical vehicles. Suitable dispersing or suspending agents for
aqueous suspensions include synthetic and natural gums such as
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tragacanth, acacia, alginate, dextran, sodium carboxymethylcellulose,
methylcellulose, polyvinyl-pyrrolidone or gelatin.
Compositions of the present invention may also be administered via
the buccal cavity using conventional technology, for example, absorption
wafers.
Compositions in the form of tablets, pills, capsules or wafers for oral
administration are particularly preferred.
A minimum dosage level for the NK-1 receptor antagonist is about
1mg per day, preferably about 5mg per day and especially about lOmg per
day. A maximum dosage level for the NK-1 receptor antagonist is about
1500mg per day, preferably about 1000mg per day and especially about
500mg per day. The compounds are administered once a day.
It will be appreciated that the amount of the NK-1 receptor
antagonist required for use in the treatment or prevention of bipolar
disorders will vary not only with the particular compounds or compositions
selected but also with the-route of administration, the nature of the
condition being treated, and the age and condition of the patient, and will
ultimately be at the discretion of the patient's physician or pharmacist.
Two compounds of use in the present invention which are described
in International Patent Application No. PCT/GB97/01630 may be prepared
according to the following methods:
PREPARATION 1
(25'7-1-tert-Butoxycarbonyl-2-phenylpineridin-3-one
Dimethyl sulfoxide (20.80m1, 22.908, 29.3mmo1) in dichloromethane
(75m1) was added dropwise to a cooled (-70°C) solution of oxalyl
chloride
(13.95m1, 20.308, 160mmo1) in dichloromethane (350m1). The mixture was
stirred at -70°C for 15 minutes, then (2S,3S)-1-tert-butoxycarbonyl-3-
hydroxy-2-phenylpiperidine (prepared by the method described in
European Patent Specification number 0 528 495-A; 36.91 g, 133mmo1) in
dichloromethane (150m1) was added dropwise. The mixture was stirred at
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-70 °C for 20 minutes, then allowed to warm to -30°C. The
mixture was
cooled to -50 °C and triethylamine (55.95m1, 40.458, 400mmo1) was added
slowly. The mixture was allowed to warm to 0°C and diluted with ice-
cooled dichloromethane (250m1). The mixture was washed with ice cold
aqueous citric acid solution (5%, 2x300m1) and water (300m1), dried
(MgS04), and the solvent was evaporated under reduced pressure to give
the title compound as a yellow oil (42.38), which was used immediately
without further purification. 1H NMR (250MHz, CDCls} & 7.5-7.3 (5H, m),
5.8 (1H, br s), 4.2 (1H, br s), 3.4 (1H, m), 2.6 (2H, m), 2.0 (2H, m), and
1.54
(9H, s).
PREPARATION 2
(2S, 3R)-1-tert-Butoxvcarbonyl-3-hydroxy-3-(2-methylene-3-
phenoxypropvl)-2-phenylpiperidine
A solution of 3-(chloromagnesio}-2-(phenoxymethyl)-1-propene in
THF (0.91M, 3m1) (Louw et. al., Tetrahedron, 48; 6087-6104, 1992,
prepared from 2.74mmo1 of 3-chloro-2-(phenoxymethyl)-1-propene) was
slowly added to a solution of (25'~-1-tent-butoxycarbonyl-2-phenylpiperidin-
3-one (Preparation 1) in THF (3m1). The mixture was stirred at room
temperature for 1 hours) then saturated aqueous ammonium chloride
(20m1) was added and the mixture was extracted with ethyl acetate
(20m1). The organic phase was washed with brine, dried (MgSO~) and the
solvent was evaporated under reduced pressure . The residue was purified
by column chromatography on silica gel, eluting with hexane/ethyl acetate
(100:0 increasing to 80:20) to give the title compound. 1H NMR (360MHz,
CDCla) 8 7.48 (2H, d) J=6.9 Hz), 7.35-7.2 (6H, m), 6.9-6.88 (3H, m), 5.4
(1H, s), 5.15 (2H, d, J=13.7 Hz), 4.61 (2H, s), 4.11 (2H, m), 3.17 (1H, m),
2.66 and 2.59 (2H, AB d, J=14.0 Hz), 1.95 (2H, m), 1.79 (2H, m), and 1.36
(9H, s). m/z (ES+) 424 (M+1).
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PREPARATION 3
(5R,6S)-3-Methylene-6-phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-
spiro[4.51decane
To a cooled(-80 °C) solution of (2S,3R)-1-tert-butoxycarbonyl-3-
hydroxy-3-(2-methylene-3-phenoxypropyl)-2-phenylpiperidine (Preparation
2, 1.53g, 3.62mmol) in THF (20m1) was added n-butyl lithium (2.5M in
hexanes, 1.45m1, 3.62mmo1) followed by a solution of zinc chloride (0.5M in
THF, 7.24m1, 3.62mmol). The solution was allowed to warm to room
temperature and tetrakis(triphenylphosphine)palladium (0) (0.23g)
0.2mmo1) was added. The mixture was degassed with bubbling nitrogen
and heated under reflux for 16 hours. The mixture was cooled and the
solvent was evaporated under reduced pressure.The residue was
partitioned between ethyl acetate and 2M sodium hydroxide. The organic
phase was washed with saturated brine, dried (MgS04) and purified by
chromatography on a column containing silica gel (eluting with hexane
containing increasing proportions of ethyl acetate between 0% to 5%).
Evaporation of the fractions gave (6S, 5R)-3-methylene-6 phenyl-1-oxa-7-
(tert-butoxycarbonyl)aza-spiro~4.5Jdecane. 1H NMR (360MHz, CDCIs) 8
7.58 (2H, d, J=8.4 Hz), 7.32-7.21 (3H, m), 5.23 (1H, s), 5.06 (1H, m), 4.97
(1H, m), 4.39 (2H, AB d, J=13.3 Hz), 3.99 (1H, dd, J=13.3, 4.48 Hz), 2. 83
(1H, ABd J=15.5 Hz), 2.7 (lH,td J=12.5, 3.93 Hz), 2.5 (1H, ABd, J=15.4
Hz), 2.15 (2H, td, J=12., .4_ Hz), 1.69 (2H, m), and 1.46 (9H,s). m/z (ES+)
329 {M+2H-tBuOCO).
PREPARATION 4
(5R,6S'7-3-Keto-6-phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-spiro[4.5]Idecane
Through a cooled (-80 °C) solution of (5R,6S)-3-methylene-6-phenyl-
1-oxa-7-(tent-butoxycarbonyl)aza-spiro[4.5)decane (Preparation 3; 0.665g)
in dichloromethane (5m1) and methanol (5m1) was bubbled a mixture of
ozone and oxygen for 45 minutes. After the solution had been purged with
nitrogen, dimethyl sulphide (0.5m1) was added and then stirred under
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nitrogen at room temperature for 16 hours. The solvent was removed in
u~zcuo and the residue partitioned between ethyl acetate and water. The
organic phase was dried (MgS04), evaporated and the residue purified by
chromatography on a column containing silica gel (eluting with hexane
containing increasing proportions of ethyl acetate between 0% to 10%).
Evaporation of the fractions gave the title compound. 1H NMR (250MHz,
CDCls) s 7.58 (2H, d, J=6.2 Hz), 7.37-7.26 (3H, m), 5.3 (1H, s), 4.15 and
4.09 (2H, AB d, J=17.4 Hz), 3.97 (1H, m), 2.80 (1H, td, J=12.9, 4.0 Hz))
2.74 and 2.48 {2H, ABd, J=18.1 Hz), 2.29 (2H, m), 1.88-1.63 (2H, m), and
1.44 (9H, s). m/z (ES+) 332 (M+I).
PREPARATION 5
(5R,6S7-3-Trifluoromethylsulfonyloxy-6-phenyl-I-oxa-7-(tert-
butoxycarbonyl)aza-spiro[4.5idec-3-ene
To a cooled (-80 °C) solution of 1M sodium hexamethyldisilazide
(0.38m1, 0.38mmo1) in THF was added a solution of (5R,6.5~-3-keto-6-
phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-spiro[4.5]decane (Preparation 4;
0.105mg, 0.319mmo1) in THF (3ml). The solution was stirred for 1 hours
at -80°C then a solution of 2-[N,N-bis{trifluoromethylsulfonyl)amino]-5-
chloropyridine (0.1638, 0.4I5mmo1) in THF (3m1) was added. The solution
was stirred at -80°C for 30 minutes then at room temperature for 30
minutes before being quenched by addition of saturated ammonium
chloride solution and ethyl acetate. The dried (MgS04) organic phase was
purified by chromatography on a column containing silica gel {eluting with
hexane containing increasing proportions of ethyl acetate between 0% to
5%). Evaporation of the fractions gave the title compound. 1H NMR
(360MHz, CDCls} 8 7.4 (2H, d, J=7.3 Hz)) 7.3-7.22 (3H, m), 6.0I (1H, t,
J=2.13 Hz), 5.13 (1H, s), 4.56 and 4.26 (2H, ABdd, J=12.4, 1.97 Hz},4.10
(1H, dt, J=12.6, 4.22 Hz), 3.00 (1H) m), 2.28-2.04 (2H, m), 1.88-I.76 (2H,
m), and 1.37 (9H, s). m/z (ES+) 464 (M+1).
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PREPARATION 6
(5R,6S'7-3-Trimethylstannyl-6-phenyl-1-oxa-7-(tent-butoxycarbonyDaza-
~iro j4. 5] dec-3-ene
To a degassed solution of (5R,65'~-3-trifluoromethylsulfonyloxy-6-
phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-spiro[4.5]dec-3-ene (Preparation
5; 0.4828, 1.04mmo1), lithium chloride (0.2648, 6.25mmo1), lithium
carbonate (0.0768) and hexamethyl distannane(0.96g, 2.9mmo1) in THF
(lOml) was added triphenylphosphine palladium (0) (0.068). The solution
was degassed and then heated at 60°C for 5 hours under nitrogen. Water
(20m1) and ethyl acetate (20m1) were added and the dried organic phase
was purified by chromatography on a column containing silica gel (eluting
with hexane containing increasing proportions of ethyl acetate between 0%
to 5%). Evaporation of the fractions gave the title compound as a
crystalline solid. 1H NMR (360MHz, CDCIs) 8 7.25 (2H, d, J=7.3 Hz), 7.1-
7.0 (3H, m), 5.83 (1H, t, J=2.5 Hz), 4.78 (1H, s), 4.48 and4.02 (2H, dd,
J=12.9, 2.3 Hz), 3.96 {1H, dd, J=6.16, 13.4 Hz), 2.95 (1H, td, J=13.3, 4.5
Hz), 1.84 (1H, m), 1.68 (1H, m}, 1.60 (2H, m}, 1.19 (9H, s), and 0.0 {6H, s).
PREPARATION 7
( _2S.3R1-1-tert-Butoxycarbonyl-3-(3-hydroxyuropyn-1-yl)-2-phenylpiperidin-
3-0l
O-Trimethylsilylpropargyl alcohol (24.51m1, 20.478, 160m1) was
added slowly to a cooled (-10°C) solution of ethylmagnesium bromide (1M
in tetrahydrofuran, 160m1, 160mmo1). The mixture was stirred at 0°C for
20 minutes, then at room temperature for 2 hours. The mixture was
cooled to -10°C and a solution of (2S')-1-tert-butoxycarbonyl-2-
phenylpiperidin-3-one (Preparation 1; 42.38) in tetrahydrofuran (200m1)
was added dropwise over 30 minutes. (Internal temperature below -5°C).
The mixture was stirred at room temperature for 14 hours, poured into
water (300m1) and saturated aqueous ammonium chloride (300m1) and
extracted with ethyl acetate (2x300m1). The combined organic fractions
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were washed with brine (300m1), dried (MgS04) and the solvent was
evaporated under reduced pressure. The residue was dissolved in ethyl
acetate (500m1) and a solution of tetrabutylammonium fluoride {1M in
THF, 160m1, 160mmo1) was added dropwise. The mixture was stirred at
room temperature for 30 minutes, water (300m1) was added, and the
layers were separated. The aqueous layer was extracted with ethyl
acetate (2x300m1) and the combined organic fractions were washed with
water {300m1) and brine (300m1), dried (MgS04) and the solvent was
evaporated under reduced pressure to give the crude title compound as an
orange oil (45g}. The crude material was purified by flash column
chromatography on silica gel, eluting with hexane/ethyl acetate (90:10
increasing to 25:75} to give the title compound as an amber oil (32.2g). 1H
NMR (CDCls) 8 7.53-7.55 (2H, m), 7.19-7.35 (3H, m), 5.56 (1H, s), 4.27 (2H,
s), 3.99-4.03 (1H, m), 3.25 (1H, br s), 2.77-2.81 (1H, m), 2.77 (1H, br s),
2.12-2.20 (1H, m), 1.91-1.99 (2H, m), 1.77-1.83 (1H, m), and 1.39 (9H, s).
PREPARATI(JN 8
2-Bromo-4-(trifluoromethoxy)phenol
To a cooled (0 °C) solution of 4-trifluoromethoxyphenol (35.68,
0.2mo1) in chloroform (280m1) was added dropwise a solution of bromine
(32g, 0.2mo1) in chloroform (50m1). The solution was stirred at 0°C for
1
hour and at room temperature for 2 hours. Dichloromethane (200m1) and
water (400m1) ware added and the organic phase was washed further with
water(400m1), brine (200m1) and dried {MgSO4). The solvent was removed
and the residue was purified by distillation at reduced pressure to give the
title compound. 1H NMR (250MHz, CDCls) 8 7.38 (1H, d, J=2.1 Hz), 7.13
(1H, dd, J=9.1, 2.1 Hz), 7.03 (1H, d, J=9.I Hz), and 5.53 (1H, s).
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PREPARATION 9
2-Benzyloxy-5-(trifluoromethoxy}bromobenzene
2-Bromo-4-(trifluoromethoxy)phenol (Preparation 8; 5g, 20mmo1)
was dissolved in N,N-dimethylformamide (60m1), and potassium carbonate
(5.4g, 40mmo1) was added, followed by benzyl bromide (3.5m1, 30mmo1),
and the reaction was stirred at ambient temperature for 15 hours. The
reaction was diluted with water (150m1) and extracted into ethyl acetate
(3x60m1). The combined organic fractions were washed with water
(100m1), brine (100m1), dried (MgS04) and evaporated in vacuo.
Purification on silica, eluting with 2% and 5°/ ethyl acetate in
hexane gave
the title compound as a clear oil (6.7g, 96%). 1H NMR (250MHz, CDCls) 8
5.47 (2H, s), 7.23 (1H, d, J=9 Hz), 7.43 (1H, dd J=8.2, 2.9 Hz), and 7.75
(6H, m).
PREPARATION 10
Z-(2S, 3R)-1-tert-Butoxycarbonyl-3-(3-hydroxynrop-1-a n-1-yl}-2-
phenylpiueridin-3-of
Palladium on calcium carbonate, poisoned with lead (Lindlar
catalyst, 2g) was added to a solution of (2S,3R)-1-tert-butoxycarbonyl-3-(3-
hydroxypropyn-1yl)-2-phenylpiperidin-3-of (Preparation 7; 32g, 96.6mmo1)
in ethyl acetate (300m1) and .the mixture was stirred under hydrogen {1
atmosphere) for 4 hours. The mixture was filtered and the solvent was
evaporated under reduced pressure to give the title compound as an oil
(32g, 100%). 1H NMR (360MHz, CDCia) 8 7.42 (2H, d, J=7.6 Hz), 7.35-7.25
(3H, m), 5.83 (1H, d, J12.3 Hz), 5.68 (1H, dt, J=12.3, 6.0 Hz), 5.06 (1H, s),
4.27 (1H, m), 4.12 (2H, m), 3.32 (1H, m), 3.13 {1H, s), 2.28 (1H, t, J=5.9
Hz), 2.02 (1H, m), 1.92-1.78 (3H, m), and 1.32 (9H, s). m/z (ESA) 334 (M+1).
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PREPARATION 11
(5R,6f~-6-Phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-spiro[4 5],dec-3-ene
Diethylazodicarboxylate (18.2m1, 115mmol) in THF (100m1) was
added dropwise to a solution of Z-(2S,3R)-1-tent-butoxycarbonyl-3-(3-
hydroxyprop-1-en-1-yl)-2-phenylpiperidin-3-of (Preparation 10; 328,
96mmol) and triphenylphosphine (30.28, 115mmo1) in THF (700m1). The
mixture was stirred at 0°C for 30 minutes then at room temperature for
1.5 hours. The solvent was evaporated under reduced pressure and the
residue was purified by flash column chromatography on silica gel, eluting
with hexane/ethyl acetate (95:5 increasing to 80:20) to give the title
compound as a colorless solid (23.48, 77%). 1H NMR (CDCIs) 8 7.45 (2H, d,
J=7.4 Hz), 7.27 (2H, t, J=7.4 Hz), 7.20 (IH, t, J=7.4 Hz), 6.03 {1H, dt,
J=6.1, 2.0 Hz), 5.68 (1H, dt, J=6.1, 2.0 Hz), 5.06 (1H, s), 4.61 (1H, dt,
J=13.1, 2.0 Hz), 4.32 (1H, dt, J=13.1, 2.0 Hz), 4.08 (1H, m), 3.05 (1H, m),
2.05 (1H, m), 1.75 (3H, m), and 1.37 (9H, s). m/z {ES+) 316 (M+1).
' PREPARATION 12
2-Benzyloxy-5-(trifluoromethoxy)benzene
Benzyl bromide (66.17m1, 95.358, 0.56mo1) was added to a mixture
of 4-(trifluoromethoxy)phenol (90.268, 0.51mo1) and potassium carbonate
(140.978, l.2mo1) in dimethylformamide (160m1) and the mixture was
stirred at room temperature for 72 hours. The mixture was poured into
water (1.51) and extracted with ethyl acetate (3x500m1). The combined
organic fractions were washed with aqueous sodium carbonate (saturated,
500m1), dried (MgS04) and the solvent was evaporated under reduced
pressure to give the title compound as a colorless solid (133.58,
99°/). 1H
NMR (360MHz, CDCls) 8 7.39 (5H, m), 7.14 (2H, d, J=9.0 Hz), 6.95 (2H, d,
J=9.0 Hz), and 5.05 (2H, s).
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PREPARATION 13
2-Benzyloxy-5-(tr ifluorometho~)iodobenzene
Iodine (71.96g, 0.28mo1) in chloroform was added dropwise to a
mixture of 2-benzyloxy-5-(trifluoromethoxy)benzene (Preparation 12,
5 73.068, 0.27mo1) and silver trifluoroacetate (71.578, 0.32mo1) in
dichloromethane and the mixture was stirred at room temperature for 18
hours. The mixture was filtered through celite, washed with aqueous
sodium thiosulfate (5%, 2x21), dried (MgS04) and the solvent was
evaporated under reduced pressure. The residue was purified by flash
10 column chromatography on silica gel, eluting with hexane/ethyl acetate, to
give the title compound as a colorless oil (108.038), containing 11%
unreacted 2-benzyloxy-5-(trifluoromethoxy)iodobenzene. 1H NMR
(360MHz, CDCls) b 7.67 (1H, d, J=2.s Hz), 7.40 (5H, m), 7.16 (1H, dd,
J=8.9, 2.8 Hz), 6.82 (1H, d, J=8.9 Hz), and 5.14 (2H, s).
-PREPARATION 14
(5R.6,f7-3-(2-Benzyloxy-5-(triouoromethoxy)phenyl)-6-phenyl-1-oxa-7-(tert-
butoxycarbonyDaza-spiro[4.5]dec-3-ene
(5R,6S}-3-Trimethylstannyl-6-phenyl-1-oxa-7-(tert-
butoxycarbonyl)aza-spiro[4.5]dec-3-ene (Preparation 6; 6.43mmo1), lithium
chloride (0.1638), benzyloxy-5-(trifluoromethoxy)phenol (Preparation 9;
7.7mmo1) in toluene (25m1} was degassed before addition of
triphenylphosphine palladium (0) (0.378). The solution was degassed
thoroughly before heating to 110°C for 14 hours. The solution was
partitioned between water and ethyl acetate and the dried organic phase
was purified by chromatography on a column containing silica gel (eluting
with hexane containing increasing proportions of ethyl acetate between 0%
to 4%) to give the title compound. 1H IVMR (360MHz, CDCls) 8 1.33 (9H,
s), 1.65 (1H, m}, 1.76 (2H, m), 2.08 (1H, m), 3.11 (1H, m), 4.08 (1H, m),
4.60 (1H, dd, J=12.2 Hz, J=2 Hz), 4.92 (1H, dd, J=12.1 Hz, J=1.8 Hz), 5.08
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(1H, s), 5.1 (2H, q, J=11.5 Hz), 6.65 (1H, s), 6.94 (2H) d, J=8.9 Hz), 7.08
(1H, d, J=9 Hz), 7.18 (2H, t, J=8.1 Hz), ?.25 (3H, m), 7.38 (5H, m).
PREPARATION 15
(3S,5R,65'7-3-(2-Hydroxy-5-(trifluoromethoxy)phenyl)-6-phenyl 1 oxa 7
tent-butoxycarbonyl)aza-spirof4 5]'decane
(5R, 6S)-3-(2-Benzyloxy-5-(trifluoromethoxy)phenyl)-C-phenyl-1-oxa-
7-(tert-butoxycarbonyl)aza-spiro[4.5)dec-3-ene (Preparation 14) (3.88g) was
dissolved in ethyl acetate (15m1) and methanol (15m1). Palladium
hydroxide on carbon (l.OOg) was added and the suspension was shaken
under a hydrogen atmosphere (50 psi) for 72 hours. The mixture was
filtered and the solvent was evaporated under reduced pressure. The .
residue was purified by medium pressure chromatography on silica gel,
eluting with hexane/ethyl acetate (75:25) to give (3R, 5R, 6S)-3-(2-hydroxy-
5-(trifluoromethoxy)phenyl)-6 phenyl-1-oxa-7 (tent-butoxycarbonyl)aza-
spiroj4.5Jdecane (191mg), ~H N1VIR (250MHz, CDC13) 8 7.70 (2H, d, J=7.3
Hz), 7.33 (2H, t, J=7.3 Hz), 7.26 (1H, d, J=7.3 Hz), 7.05 (1H, br s), 6.96
(2H, m), 6.82 (IH, d, J=9.4 Hz), 5.43 (1H, s), 4.27 (1H, m), 4.OI (1H, m),
3.95 (1H, m), 3.73 (1H, m), 2.73 (2H, m), 2.33 (1H, m), 1.87-1.58 (4H, m);
and 1.50 (9H, s).and (3S,5R,6S)-3-(2-hydroxy-5-(trifluoromethoxy)phenyl)-
6 phenyl-1-oxa-7-(tent-butoxycarbonyd)aza-spiro~4.5Jdecane (2.3g), 1H NMR
(360MHz, CDCIs) 8 1.38 (9H, s), 1.73 (2H, m), 1.81 (1H, m), 2.18 (2H, m),
2.50 (1H, m), 2.81 (1H, m), 3.62 (1H, t, J=7.2 Hz), 3.92 (1H, m), 3.98 (1H,
d, J=13.2 Hz), 4.23 (1H, m), 5.33 (1H, s), 6.75 (1H, d, J=8.5 Hz), 6.94 (2H,
m}, 7.25 (1H, m), 7.31 (2H, m), and 7.55 (2H, d, J=7.8 Hz).
PREPARATION 16
3R,5R,6S'7-3-(2-Benzyloxy-5-(trifluoromethoxy)phenyl)-6-phenyl 1 oxa ?
(tent-butoxycarbonyl)aza-spiro f 4. 5] decane
A mixture of 2-benzyloxy-5-(trifluoromethoxy)iodobenzene
(Preparation 13, 21.88, 55.2mmo1), {5R,6S~-6-phenyl-1-oxa-7-(tert-
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2Z
butoxycarbonyl)aza-spiro[4.5]dec-3-ene (Preparation 11, 7.Og,. 22.lmmol),
tetra-n-butylammonium chloride (6.18g, 22.2mmo1), lithium chloride
(9.35g, 0.22moI) and potassium formate (5.648, 67.Ommol) in
dimethylformamide (100m1) was degassed with a firestone valve (5 x).
Palladium acetate {491mg, 2.2mmo1) was added and the mixture was
degassed with a firestone valve (5 x). The mixture was stirred at 60°C
for
hours, then further 2-benzyloxy-5-(trifluoromethoxy}iodobenzene
(Preparation 13, 4.328, ll.Ommo1), potassium formate (2.78g, 33.5mmol}
and palladium acetate (260mg, l.lmmol) were added. The mixture was
10 stirred at 60°C for 22 hours, cooled and filtered. The solvent was
evaporated under reduced pressure, water (600m1) was added and the
mixture was extracted with ethyl acetate (2x300m1). The combined
organic fractions were washed with brine (300m1), dried (MgS04) and the
solvent was evaporated under reduced pressure. The residue was purified
15 by flash column chromatography on silica gel, eluting with
hexane/dichloromethane {75:25 increasing to 0:100) then
dichloromethane/ethyl acetate (95:5), to give the title compound (9.42g,
73%). iH NMR (360MHz, CDCls) 8 7.56 (2H, d, J=7.7 Hz), 7.40-7.20 {8H,
m), 7.14 (1H, d, J=2.0 Hz), 7.00 (1H, dd, J=8.9, 2.0 Hz), 6.88 (1H, d, J=8.9
Hz), 5.30 (1H, s), 5.08 (2H) s), 4.27 (1H, m), 3.97 (1H, m), 3.87 (2H, m),
2.78 (1H, m), 2.56 {1H, m), 2.15 (1H, m), 1.96 (1H, m), 1.67 (3H, m), and
1.42 (9H, s).
PREPARATION I7
~3R,5R.65~-3-(2-Hydroxy-5-(triffuoromethoxy)phenyl)-6-phenyl-1-oxa-7-
(tert-butoxycarbonyDaza-spiroj4.5)decane
Palladium on carbon (10%, 0.59g) was added to a solution of
(3R, 5R, 6S~-3-(2-benzyloxy-5-(trifluoromethoxy)phenyl)-6-phe nyl-1-oxa-7-
(tert-butoxycarbonyl)aza-spiro[4.5]decane (Preparation 16, 6.lOg,
10.5mmol) in methanol-water (99:1, 200mi) and the mixture was stirred
under hydrogen (50 psi.) for 72 hours. The mixture was filtered, washing
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with ethanol, and the solvent was evaporated under reduced pressure.
The residue was purified by flash column chromatography on silica gel,
eluting with dichloromethane/ethyl acetate (99:1 increasing to 90:10) to
give the title compound. 1H NMR (360MHz, CDCIs) 8 7.70 (2H, d, J=7.3
Hz), 7.33 (2H, t, J=7.3 Hz), 7.26 (1H, d, J=7.3 Hz), 7.05 (1H, br s), 6.96
(2H, m), 6.82 (1H, d, J=9.4 Hz), 5.43 (1H, s), 4.27 (1H, m), 4.OI (1H, m),
3.95 (1H, m), 3.73 {1H, m), 2.73 (2H, m), 2.33 (1H, m), 1.87-1.58 (4H, m),
and 1.50 (9H, s).
PREPARATION 18
(3S.5R,6S)-3-[2-(1-Phenylthiocyclopro~p-1- 1)oxy-5-
(trifluoromethoxy)phen ly 1-6-phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-
spiro[4.5]decane
(3S,5R,6S)-3-(2-Hydroxy-5-(trifluoromethoxy)phenyl)-6-phenyl-1-
I5 oxa-7-(tert-butoxycarbonyl)aza-spiro[4.5]decane (Preparation 15) (290mg,
0.59mmo1) was dissolved in toluene (5ml) and silver carbonate (179mg,
0.65mmol) was added in one portion. (1-Iodocycloprop-1-yl)phenylsulfide
(Cohen T. and Matz J. R., J. Am. Chem. Soc. 1980, 102, 6902) (180mg,
0.65mmol) was then added over one minute at room temperature. The
mixture was stirred at 55°C for 4 hours, then further portions of
silver
carbonate (179mg, 0.65mmol) and (1-iodocycloprop-1-yI)phenylsulfide
(180mg, 0.65mmol) were added. The mixture was stirred at 55°C for a
further 3 hours, cooled, filtered and the solvent was evaporated under
reduced pressure. The residue was purified by column chromatography on
silica gel, eluting with hexanelethyl acetate (90:10 increasing to 80:20) to
give the title compound as a colourless oil (120mg, 32%). 1H NMR
(250MHz, CDCls) 8 7.55-7.44 (4H, m), 7.36-7.23 (7H, m), 7.13-7.02 (2H, m),
5.16 (1H, br s), 4.09 (1H, t, J=6 Hz), 4.03-3.92 (1H, m), 3.67-3.49 (2H, m),
2.94-2.79 (1H, m), 2.26 (1H, dd, J=7.9) 12.9 Hz), 2.15-2.01 (2H, m), 1.76-
1.59 (3H, m), 1.53-1.45 (4H, m)) and 1.36 (9H, s). m/z (ES+) 642 (M+1).
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- PREPARATION 19
(3R.5R,6S'7-3-[2-(1-Phenylthiocycloprop-1-yl)oxy-5-
(trifluoromethoxy)phenyll-6-phenyl-1-oxa-7-(tert-butoxycarbonyl aza-
spiro [4.5]I decane
Prepared from (3R,5R,6S)-3-{2-hydroxy-5-
(trifluoromethoxy)phenyl)-6-phenyl-1-oxa-7-(tent-butoxycarbonyl)aza-
spiro[4.5]decane (Preparation 17) according to the method of Preparation
18. 1H NMR (360MHz, CDCIs) s 7.57 (2H, app. d, J=7.6 Hz)) 7.45 (2H,
app. d, J=7.7 Hz), 7.36-7.19 (7H, m), 7.16-7.06 (2H, m}, 5.28 (1H, br s),
4.13 (1H, app. t, J=7.8 Hz), 3.96 (1H, br. d, J=13 Hz), 3.80-3.60 (2H, m),
2.79 (1H, br. t, J=13 Hz), 2.50 (1H, dd, J=13, 7.9 Hz), 2.17 (1H, dt, J=13,
4.6 Hz), 1.80 (1H, dd, J=12, 9.8 Hz), 1.75-1.38 (7H, m), and 1.44 (9H, s}.
mlz {ES+) 642 (M+I).
PREPARATION 20
(3S.5R,6S)-3-j2-Cyclopropoxy-5-(trifluoromethox~phenyll-6-phenyl-1-oxa-
7-(tent-butoxycarbonyl)aza-spiro[4.51decane
Naphthalene (120mg, 0.936mmo1) was dissolved in THF (l.5ml)
under nitrogen and freshly cut lithium metal (7.Omg, 0.94mmo1) was
added. The mixture was then sonicated at room temperature for 20
minutes to produce a dark green solution of lithium naphthalenide. This
solution was cooled to -78 °C, then (3S,5R,6S)-3-[2-(1-
phenylthiocycloprop-
1-yl}oxy-5-(trifluoromethoxy)phenyl]-6-phenyl-1-oxa-7-(tert-
butoxycarbonyl)aza-spiro[4.5]decane (Preparation 18) (120mg, 0.187mmo1)
in THF (0.5m1) was added over i minute. The reaction mixture was
stirred for 30 minutes, then water (5m1) and ether (10m1) were added. The
layers were separated and the aqueous layer was extracted with ether
(10m1). The combined organic fractions were dried (MgS04) and the
solvent was evaporated under reduced pressure. The residue was purified
by column chromatography on silica gel, eluting with hexane/ethyl acetate
(90:10 increasing to 80:20) to give the title compound as a colourless oil
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Zf
(58.6mg, 59%). 1H NMR (250MHz) CDC13) 8 7.58-7.52 (2H, m), 7.36-7.17
{4H, m), 7.10-7.01 (2H, m), 5.18 (1H, br s), 4.20 (1H, t, J=6.7 Hz), 4.05-3.95
(1H, m), 3.76-3.55 (3H, m), 2.92-2.79 {1H, m), 2.37 (1H, dd, J=12.9, 7.8
Hz), 2.18-2.06 (2H, m), 1.80-1.6? (3H, m), 1.38 (9H, s), and 0.86-0. 73 (4H,
m). m/z (ES+) 534 (M+I).
PREPARATION 21
~3R.5R,6S~-3-f2-Cyclopropoxy-5-(trifluoromethoxy)phenyl]-6-phenyl-1-oxa-
7-~tert-butoxycarbonyl)aza-spiro[4.51decane
Naphthalene (120mg) 0.936mmol) was dissolved in THF (1.5m1)
under nitrogen and freshly cut lithium metal (7.Omg, 0.94mmo1) was
added. The mixture was then sonicated at room temperature for 20
minutes to produce a dark green solution of lithium naphthalenide. A
solution of (3R,5R,6S~-3-[2-(1-phenylthiocycloprop-1-yl)oxy-5-
I5 (trifluoromethoxy)phenyl]-6-phenyl-1-oxa-7-(tent-butoxycarbonyl)aza-
spiro[4.5]decane (Preparation 19, 135mg, 0.21mmo1) in THF (2ml) under
nitrogen was cooled to -78°C and the solution of lithium naphthalenide
in
THF was added dropwise until the intense green colour persisted. The
reaction was then stirred for one minute, water (5m1) was added and the
mixture was warmed to room temperature. Ether (IOmI) was added and
the layers were separated. The aqueous phase was extracted with a
further portion of ether (lOml) and the combined organic phases were
dried (MgS04) and the solvent was evaporated under reduced pressure.
The residue was purified by column chromatography on silica gel, eluting
with hexane/ethyl acetate (50:50) to give the title compound as a colourless
oil (87mg, 78%). 1H NMR (360MHz, CDCls) 8 7.59 (2H, app. d, J=7.6 Hz),
7.32 (2H, app. t, J=7.6 Hz), 7.27-7.18 (2H, m), 7.11-7.03 {2H, m), 5.32 (1H,
br s)) 4.29-4.21 (1H, m), 3.97 (1H, br. d, J=13 Hz), 3.83-3.68 (3H, m), 2.76
(1H, dt, J=13, 4.1 Hz), 2.55 (1H, dd) J=13, 7.2 Hz), 2.22 (1H, dt, J=12, 5.2
Hz)) 1.85 (1H, dd, J=13, 9.9 Hz), 1.80-1.63 (3H, m), 1.46 (9H, s), and 0.$2-
0.76 (4H, m). m/z (ES+) 534 (M+1).
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~6
COMPOUND A
(3S. 5R, 6S~-3-L -Cyclopropoxy-5-(trifluoromethoxy)phenyl]-6~henyl-1-oxa-
7-aza-spiro f 4.51decane Hydrochloride
Trifluoroacetic acid (2.5m1) was added dropwise to a stirred, cooled
0°C) solution of (3S,5R,6S')-3-[2-cyclopropoxy-5-
(trifluoromethoxy)phenyl]-
6-phenyl-1-oxa-7-(tert-butoxycarbonyl)aza-spiro[4.5]decane (Preparation
20; 492mg, 0.92mmo1) in dichloromethane (25m1) and the mixture was
stirred at room temperature for 3 hours. The mixture was poured into
water (50m1), the pH was adjusted to I0.0 with aqueous sodium hydroxide
(4M) and the mixture was extracted with dichloromethane (3x50m1). The
combined organic fractions were dried (MgS04) and the solvent was
evaporated under reduced pressure. The residue was purified by flash
column chromatography on silica gel, eluting with
dichloromethane/methanol/ammonia (aq.) (96:4:0.4 increasing to 94:6:0.6).
The residue was dissolved iwethanol (20m1), cooled in ice and ethereal
hydrogen chloride (1M, I.8ml, l.8mmol) was added dropwise. The mixture
was stirred at 0°C for 5 minutes, then the solvent was evaporated under
reduced pressure. The residue was crystallized from ether (20m1)/ethanol
(0.5m1) and the solid was collected and dried in v~cuo to give the title
compound as a colorless solid (354mg, 89%}. m.p. 214-216 °C, 1H NMR
(500MHz, CDaOD) 8 7.59 (2H, m), 7.52 (3H, m), 7.26 (1H, d, J=8.9 Hz),
7.03 (1H, dd, J=8.9, 2.2 Hz}, 6.20 (1H, d, J=2.2 Hz), 4.85 (2H, br s)) 4.43
(1H, s), 4.19 (1H, t, J=8.0 Hz), 3.87 (1H, quin, J=8.0 Hz), 3.76 (1H, m),
3.44 (1H, m), 3.25 (2H, m) 2.29-1.78 (6H, m), 0.80 (2H, m), and 0.66 (2H,
m). mlz (ES+) 434 (M+1). Found: C, 61.41; H, 5.51; N, 3.08.
Cz4HzsFsNOs~HCl requires: C, 61.34; H, 5.79; N, 2.98%.
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2~
COMPOUND B
(3R 5R 6~S')-3-f2-Cyclopropoxy-5-(trifluoromethoxylphenyl] 6 phenyl 1 oxa
7-aza-~iro~4.51decane
Prepared from the compound of Preparation 21 according to the
method used for Compound A. 1H NMR (360MHz, CDCIs) 8 7.50-7.42 (2H,
m), 7.36-7.26 (3H, m), 7.03 (1H, d, J=8.9 Hz), 6.95 (1H, br. d, J=8.9 Hz),
6.81 (1H, br s), 3.92 (1H, t, J=7.4 Hz), 3.62-3.53 (2H, m), 3.50 (1H, s), 3.20
(1H, dd, J=12, 4.2 Hz)) 2.77 (1H, dt, J=I2, 2.8 Hz), 2.30-1.93 (4H, m), 1.87
(1H, br s), 1.71-1.49 (3H, m), 0.76-0.65 (2H, m), and 0.65-0.54 (2H, m). m/z
(ES+) 434 (M+1).
A further compound and diastereomers thereof of use in the present
invention may be prepared according to the following method:
DESCRIPTION 1
2-(1-Phenylthiocycloprop-1-yI)oxy-5-(trifluoromethoxy)benzaldehyde
Silver carbonate (1.2 g, 4.34 mmol) was added to a solution of
2-hydroxy-5-(trifluoromethoxy)benzaldehyde (0.5 g, 2.43 mmol) and
(1-iodocycloprop-1-yl)phenylsulfide (Cohen T. and Matz J. R., J. Am.
Chem. Soc. 1980, 102, 6902) (1.2 g, 4.34 mmol) in toluene (30 mL) and the
mixture was stirred at 40 °C overnight. The mixture was cooled, diluted
with ethyl acetate and filtered, washing well with ethyl acetate. The
mixture was washed with aqueous sodium hydroxide) dried (MgS04) and
the solvent was evaporated under reduced pressure. The residue was
purified by flash column chromatography on silica gel, eluting with
hexane/Et20 (95:5), to give the title compound as a yellow oil (191 mg,
27%).1H NMR (360MHz, CDCls) 8 1.51-1.56 (2H) m), 1.44-1.48 (2H, m),
7.25-7.35 (7H, m), 7.69 (1H, d, J 2.0 Hz), and 10.26 (1H, s).
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DESCRIPTION 2
2-Cyclopropoxy-5-(trifluoromethoxy)benzaldehyde
Freshly cut lithium metal (97 mg, 13.9 mmol) was added to a
solution of naphthalene (1.77 g, 13.9 mmol) in THF {20 mL) and the
mixture was sonicated at room temperature for 30 min. to produce a dark
green solution of lithium naphthalenide. A solution of
2-(1-phenylthiocycloprop-1-yl)oxy-5-(trifluoromethoxy)benzaldehyde
(Description 1, 96 mg, 0.27 mmol} in THF (2 mL) was cooled to -78 °C
and
the solution of lithium naphthalenide in THF (2 mL) was added dropwise
until the intense green colour persisted. The reaction was then stirred for
5 min., water (6 mL) was added and the mixture was warmed to room
temperature. The mixture was extracted with ethyl acetate, the combined
organic fractions were dried (MgS04) and the solvent was evaporated
under reduced pressure. The residue was purified by flash column
chromatography on silica gel, eluting with hexane/EtaO (80:20), to give to
give the title compound as a colourless oil {4 mg,- 6%). 1H NMR (360MHz,
CDCls) 8 0.86 (4H, m), 3.82-3.9 (1H, m), 7.42 (2H, m), 7.62 (1H) d, J 2.5
Hz), and 10.36 (1H, s).
DESCRIPTION 3
2-Nitro-4-(trifluoromethoxy)phenol
Iron(111)nitrate nonahydrate (1.97 g, 4.8? mmol) was added to a
solution of 4-(triffuoromethoxy)phenol (2 g, 11.24 mmol) in ethanol (20
mL) and the mixture was heated under reflux overnight. The mixture was
allowed to cool to room temperature, acidified to pH 1 with aqueous
hydrochloric acid (1M) and extracted with ethyl acetate. The combined
organic fractions were dried (MgS04), and the solvent was evaporated
under reduced pressure. The residue was purified by short column
chromatography on silica gel, eluting with hexane/EtOAc (70:30), to give
the title compound as a yellow oil (2.25 g, 89%). 1H NMR {360MHz, CDCIs)
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29
8 10.53 (1H, s), 8.01 (1H, d, J 3.0 Hz), 7.49 (1H, dd, J 9.1, 3.0 Hz), and
7.23
(1H, d, J 9.1 Hz).
DESCRIPTION 4
2-(1-Phenylthiocyclonron-1-yl)oxy-5-(trifluoromethoxy)nitrobenzene
Prepared from the compound of Description 3 according to the
method of Description 1. 1H NMR (360MHz, CDCIs) 8 7.73 (1H, d, J 2.7
Hz), 7.58 (1H, d, J 9.2 Hz), ?.50-7.24 (6H, m), 1.57-1.53 (2H, m), and
1.44-1.40 (2H, m).
DESCRIPTION 5
2-Cyclopropoxy-5-(trifluoromethoxy)benzeneamine
Prepared from the compound of Description 4 according to the
method of Description 2. 1H NMR (360MHz, CDCls) s 7.06 (1H, dd, J 2.8,
6.7 Hz}, 6.56 (2H, m), 3.83 (2H, br s), 3.74 (1H, m), and 0.79 (4H, m). m/z
(ES+) 234 (M+1).
DESCRIPTION 6
2-(1-Phenvlthiocycloprop-1-yl)oxy-5-(trifluoromethoxy)benzeneamine
Iron powder (13.5 g, 241 mmol) was added to a suspension of
2-(1-phenylthiocycloprop-1-yl)oxy-5-(trifluoromethoxy)nitrobenzene
(Description 4, 11.27 g, 30.1 mmol) in water (300 mL) and acetic acid (75
mL) and the mixture was stirred at 80 °C overnight. The mixture was
cooled and filtered through celite, washing with ether. The fltrate was
extracted with ether, the combined organic fractions were washed with
aqueous sodium hydroxide (1M), dried (MgS04), and the solvent was
evaporated under reduced pressure. The residue was purified by flash
column chromatography on silica gel, eluting with hexane/EtzO (90:10
increasing to 80:20), to give the title compound as a yellow solid (8 g, 78%).
1H NMR (360MHz, CDCls) 8 7.48 (2H, m), 7.34-7.23 (3H, m}, 7.15 (1H, d, J
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3~0
8.74 Hz), 6.60-6.56 (2H, m), 3.78 (2H, br s), 1.49-1.46 (2~1, m), and
1.39-1.35 (2H, m).
DESCRIPTION 7
2-Cyclopropoxy-5-(trifluoromethoxy)benzeneamine
Prepared from the compound of Description 6 according to the
method of Description 2. 1H NMR (360MHz, CDCls) 8 7.06 (1H, dd, J 2.8,
6.7 Hz), 6.56 (2H, m), 3.83 (2H, br s), 3.74 (1H, m), and 0.79 (4H, m}. m/z
(ES+} 234 (M+1).
DESCRIPTION 8
2-Cyclopropoxy-5-ftrifluoromethoxy)iodobenzene
An ice-cooled solution of sodium nitrite (3.55 g, 51 mmol) in water
(10 mL) was added dropwise to a stirred, cooled (0 °C) solution of
2-cyclopropoxy-5-(trifluoromethoxy)benzeneamine (Description 7, 4.8 g,
20.6 nimol) in-aqueous hydrochloric acid (5M; 300 mL}, maintaining the
internal temperature at 0 °C. The mixture was stirred at 0 °C
for 30 min.,
then potassium iodide (8.55 g, 51.5 mmol) in water {10 mL) was added
dropwise, maintaining the internal temperature at 0 °C. The mixture was
stirred at 0 °C for 30 min.) then allowed to warm up to room
temperature
and stirred until nitrogen evolution ceased. The mixture was extracted
with ether, the organic fraction was washed with aqueous sodium
thiosulfate (10%), dried (MgS04), and the solvent was evaporated under
reduced pressure. The residue was purified by flash column
chromatography on silica gel, eluting with hexane/Et20 (98:2 increasing to
95:5), to give the title compound as a colourless oil (6.23 g, 88%). 1H NMR
(360MHz, CDCIs) 8 7.62 (1H, d, J 2.4 Hz), ?.20 (1H, dd, J 9.1, 2.4 Hz), 7.15
{1H, d, J 9.1 Hz), 3.80 (1H, m), and 0.83 (4H, m).
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DESCRIPTION 9
2-Cvclopropoxy-5-(trifluoromethoxy)benzaldehyde
A solution of 2-cyclopropoxy-5-(trifluoromethoxy)iodobenzene
(Description 8, 0.344 g, 1 mmol) in toluene (2.5 mL) was degassed with
bubbling nitrogen for 10 min. Tetrakis(triphenylphosphine)palladium (0}
(15 mg) was added, the mixture was degassed with bubbling nitrogen for a
further 5 min., then carbon monoxide was bubbled through the mixture for
min. The mixture was warmed to 50 °C and a solution of tributyl tin
hydride (0.3 mL, 1.1 mmol) in toluene (5 mL) was added at a rate of 2
10 mL/h. via a syringe pump, maintaining carbon monoxide bubbling
throughout. The mixture was cooled, diluted with ether (20 mL) and
aqueous potassium fluoride solution (50%) was added. The mixture was
stirred at room temperature overnight, filtered and the layers were
separated. The organic layer was dried (MgS04), and the solvent was
evaporated under reduced pressure. The residue was purified by flash
column chromatography on silica gel, eluting with hexane/EtaO (80:20), to
give the title compound as a colourless oil. 1H NMR (360MHz, CDCIs} 8
0.86 {4H, m), 3.82-3.9 (1H, m)) 7.42 (2H, m), ?.62 (1H, d, J 2.5 Hz), and
10.36 (1H, s).
DESCRIPTION 10
(~)-(2RS~-1-tent-Butoxycarbonyl-2-t~henylpiperidin-3-one
Dimethyl sulfoxide (32.0 mL, 35.3 g, 0.45 mol) in dichloromethane
(100 mL) was added dropwise to a cooled (-?0 °C) solution of oxalyl
chloride (18.7 mL, 27.5 g, 0.22 mol) in dichloromethane (1000 mL). The
mixture was stirred at -70 °C for 15 min., then
(2S',3f~-1-tert-butoxycarbonyl-3-hydroxy-2-phenylpiperidine (prepared by
the method described in European Patent Specification number 0 528
495-A; 50 g, 0.18 mol) in dichloromethane (150 mL) was added dropwise.
The mixture was stirred at -70 °C for 1 h., then triethylamine
(125.8 mL,
91.3 g, 0.9 mol) was added slowly. The mixture was stirred at room
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3Z
temperature for 1 h., water (250 mL) and aqueous sodium hydrogen
carbonate (saturated, 250 mL) were added and the mixture was stirred at
room temperature overnight. The layers were separated and the aqueous
layer was extracted with dichloromethane (2 x 300 mL). The combined
organic fractions were washed with brine, dried (MgS04) and the solvent
was evaporated under reduced pressure. The residue was purified by flash
column chromatography on silica gel, eluting with hexane/EtOAc (90:10),
to give the title compound as a yellow oil (45.0 g, 91%). 1H NMR (250MHz,
CDCls) 8 7.5-7.3 {5H, m), 5.8 (IH, br s), 4.2 (1H, br s), 3.4 (1H, m), 2.6
(2H,
m), 2.0 (2H, m), and 1.54 (9H, s).
DESCRIPTION 11
(~)-(2R3R.2S3S)-1-(tent-Butoxycarbon l~phenylpiperidin-3-amine
A solution of hydroxylamine hydrochloride (17 g, 0.24 mol) and
sodium acetate (55.67 g, 0.41 mol) in water (150 mL) was added to a
solution of (~)-(2R,f~-1-tent-butoxycarbonyl-2-phenylpiperidin-3-one
(Description 10, 45 g, 0.16 mol) in ethanol (300 mL) and the mixture was
stirred at room temperature for 1 h. The solvent was evaporated under
reduced pressure, water was added and the mixture was extracted with
ethyl acetate. The organic fraction was washed with brine, dried (MgS04)
and the solvent was evaporated under reduced pressure. The residue was
dissolved in ethanol (400 mL) and Raney nickel (50 g) was added. The
mixture was shaken under hydrogen (40 psi) overnight, filtered and the
solvent was evaporated under reduced pressure. The residue was purified
by flash column chromatography on silica gel, eluting with CHzCIz/MeOH
(100:0 increasing to 85:15), to give the title compound as a colorless oil
(10.9 g, 24%). 1H NMR (360MHz, CDCls) b 7.43 (2H, d, J 7.0 Hz), 7.30 (3H,
m), 5.19 (1H, d, J 6.2 Hz), 4.00 (1H, m), 3.1? (2H, m), 1.90-1.64 (4H, m),
1.36 (9H, s), and 1.26 (2H, br s).
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COMPOUND C
(~~-(2R3R, 2S3S)-N-( f 2-Cyclopropoxy-5-(trifluoromethoxy)phenyl]methyll-2
-phen~piperidin-3-amine Dihydrochloride
2-Cyclopropoxy-5-(trifluoromethoxy)benzaldehyde (Description 9, 55
mg, 0.21 mmol) was added to (t)-(2R3R,2S3S)-1-(tent-butoxycarbonyl)-2-
phenylpiperidin-3-amine (Description 11, 58 mg, 0.21 mmol}) citric acid
(89 mg, 0.42 mmol) and 3A molecular sieves in dry methanol (5 mL) and
the mixtura was stirred at room temperature for 1.5 h. Sodium
borohydride (30 mg) was added and the mixture was stirred at room
temperature for 2 h. Ethyl acetate was added and the mixture was washed
with aqueous hydrochloric acid (O.1M, 2 x 25 mL) and brine (25 mL), dried
(MgS04) and the solvent was evaporated under reduced pressure. The
residue was dissolved in dichloromethane (3 mL), cooled to 0 °C and
trifluoroacetic acid (2 mL) was added slowly. The mixture was stirred at
room temperature for 1 h., the solvent was evaporated under reduced
pressure and ethyl acetate was added: The mixture was washed with
aqueous sodium hydrogen carbonate (saturated, 2 x 25 mL) and brine (25
mL), dried (MgS04) and the solvent was evaporated under reduced
pressure. The residue was purified by flash column chromatography on
silica gel, eluting with CH2C12IMeOH/NH3(Aq.) {96:4:0.4). The residue was
dissolved in ethanol (2 mL), cooled in ice and ethereal hydrogen chloride
(1M, 0.24 mL, 0.24 mmol) was added. The solvent was evaporated under
reduced pressure and the residue was recrystallised from ethanol to give
the title compound as a colorless solid (20 mg, 20%). m.p. 169-171 °C.
1H
NMR (400MHz, CDsOD) 8 0.64 (1H, m), 0.80 (3H, m), 1.99 (1H, m), 2.24
(1H, m), 2.46 (2H, m), 3.30 (1H, m), 3.64 (1H, m), 3.75 (2H, m), 3.96 (1H,
br s), 4.08 (1H, m)) 4.95 (1H, s), 7.23 (1H, s), 7.31 (1H, d, J 9.0 Hz), 7.37
(1H, d, J 9.0 Hz)) 7.54 (3H, m), and 7.67 (2H) m). m/z (ES+) 407 (M+1).
Particularly preferred NK-1 receptor antagonists of use in the
present invention are compounds which are potent NK-I receptor
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3y
antagonists, i.e. compounds with an NK-1 receptor affinity (ICSO) of less
than lOnM, favourably less than 2nM and preferably less than lnM.
The class of orally active, long acting, CNS-penetrant NK-1 receptor
antagonists of use in the present invention is identified using a
combination of the following assays:
ASSAY 1: NK-1 Receptor bindine
NK-1 receptor binding assays are performed in intact Chinese
hamster ovary {CHO) cells expressing the human NK-1 receptor using a
modification of the assay conditions described by Cascieri et al, J.
Pharmacol. Exp. Ther., 1992, 42, 458. Typically, the receptor is expressed
at a level of 3x105 receptors per cell. Cells are grown in monolayer
culture, detached from the plate with enzyme-free dissociation solution
(Speciality Media Inc.), and washed prior to use in the assay. lzSl-TyrB-
substance P (0.lnM, 2000Ci/mmol; New England Nuclear) is incubated in
the presence or absence of test compounds (dissolved in 5~1
dimethylsulphoxide, DMSO) with 5x104 CHO cells. Ligand binding is
performed in 0.25m1 of 50mM Tris-HCI, pH7.5, containing 5mM MnCla,
150mM NaCl, 0.02% bovine serum albumin (Sigma), 50~ig/m1 chymostatin
(Peninsula), 0.lnM phenyhnethylsulphonyl fluoride, 2~.g/ml pepstatin,
2~g1m1 leupeptin and 2.8~g1m1 furoyl saccharine. The incubation proceeds
at room temperature until equilibrium is achieved (>40 minutes) and the
receptor-ligand complex is harvested by filtration over GFIC filters pre-
soaked in 0.1% polyethylenimine using a Tomtek 96-well harvester. Non-
specific binding is determined using excess substance P (1~M) and
represents <10°/ of total binding.
ASSAY 2: Gerbil Foot-Tapping
CNS-penetrant NK-1 receptor antagonists for use in the present
invention can be identified by their ability to inhibit foot tapping in
gerbils
induced by anxiogenic agents (such as pentagastrin} or central infusion of
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NK-1 receptor agonists such as GR73632, or caused by aversive
stimulation such as foot shock or single housing, based on the method of
Rupniak & Williams, Eur. J. Phar~nacol., 1994) 265, 179.
Male or female Mongolian gerbils (35-70g) are anaesthetised by
inhalation of an isofluraneloxygen mixture to permit exposure of the
jugular vein in order to permit administration of test compounds or vehicle
in an injection volume of 5ml/kg i.v. Alternatively, test compounds may be
administered orally or by subcutaneous or intraperitoneal routes. A skin
incision is then made in the midline of the scalp to expose the skull. An
anxiogenic agent (e.g. pentagastrin) or a selective NK-1 receptor agonist
(e.g. GR73632 (d Ala[L-Pro~,Me-Leui~]-substance P-(?-11)) is infused
directly into the cerebral ventricles (e.g. 3pmo1 in 5~1 i.c.v., depending on
test substance) by vertical insertion of a cuffed 27 gauge needle to a depth
of 4.5mm below bregma. The scalp incision is closed and the animal
allowed to recover from anaesthesia in a clear perspex observation box
(25cm x 20cm x 20cm). The duration and/or intensity of hind foot tapping
is then recorded continuously for approximately 5 minutes. Alternatively,
the ability of test compounds to inhibit foot tapping evoked by aversive
stimulation, such as foot shock or single housing, may be studied using a
similar method of quantification.
ASSAY 3: Ferret Emesis
Individually housed male ferrets (1.0 -2.5 kg) are dosed orally by
gavage with test compound. Ten minutes later they are fed with
approximately 1008 of tinned cat food. At 60 minutes following oral
dosing, cisplatin (lOmg/kg) is given i.v. via a jugular vein catheter
inserted under a brief period of halothane anaesthesia. The catheter is
then removed, the jugular vein ligated and the skin incision closed. The
ferrets recover rapidly from the anaesthetic and are mobile within 10-20
minutes. The animals are observed continuously during recovery from the
anaesthetic and for 4 hours following the cisplatin injection, after which
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time the animals are killed humanely. The numbers of retches and vomits
occurring during the 4 hours after cisplatin administration are recor ded by
trained observers.
ASSAY 4: Separation-Induced Vocalisation
Male and female guinea-pigs pups are housed in family groups with
their mothers and littermates throughout the study. Experiments are
commenced after weaning when the pups are 2 weeks old. Before entering
an experiment, the pups are screened to ensure that a vigorous
IO vocalisation response is reproducibly elicited following maternal
separation. The pups are placed individually in an observation cage (55cm
x 39cm x l9cm} in a room physically isolated from the home cage for 1.5
minutes and the duration of vocalisation during this baseline period is
recorded. Only animals which vocalise for longer than 5 minutes are
employed for drug challenge studies (approximately 50% of available pups
may fail to reach this criterion). On test days each pup receives an oral
dose or an s.c. or i.p. injection of test compound or vehicle and is then
immediately returned to the home cage with its mother and siblings for 30
to 60 minutes (or for up to 4 hours following an oral dose, dependent upon
the oral pharmacokinetics of the test compound) before social isolation for
15 minutes as described above. The duration of vocalisation on drug
treatment days is expressed as a percentage of the pre-treatment baseline
value for each animal. The same subjects are retested once weekly for up
to 6 weeks. Between 6 and 8 animals receive each test compound at each
dose tested.
As used herein, the term "CNS-penetrant" refers to NK-1 receptor
antagonists which are able to inhibit NK-1 receptor antagonist-induced
foot-tapping in the gerbil as hereinafter defined.
Essentially, hind foot-tapping in the gerbil induced by infusion of
the NK-1 receptor agonist, GR73632 (d Ala[l,-Pro~,Me-Leul~]-substance P-
(7-11)}, under anaesthesia, directly into the central ventricles is inhibited
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when a CNS-penetrant NK-1 receptor antagonist is administered
intravenously immediately prior to GR73632 challenge, wherein hind foot-
tapping over a period of five minutes following recovery from the
anaesthesia is inhibited with an IDso<3mg/kg, and preferably with an
IDso<lmg/kg.
In an alternative method, the NK-1 receptor antagonist is
administered orally, 1 hour prior to GR73632 challenge, wherein the foot-
tapping over a period of five minutes following recovery from anaesthesia
is inhibited with an IDsoS30mglkg, and preferably with an IDso510mg/kg.
CNS-penetrant NK-1 receptor antagonists of use in the present
ivnention are also effective in the attenuation of separation-induced
vocalisations by guinea-pig pups as hereinafter defined.
Essentially, a vocalisation response in guinea-pig pups is induced by
isolation from their mothers and littermates, which response is attenuated
when a CNS-penetrant NK-1 receptor antagonist is administered
subcutaneously 30 minutes prior to isolation, wherein vocalisations during
the~rst 15 minutes of isolation are attenuated with an IDso__<20mg/kg,
preferably with an IDso<_l0mg/kg, and especially with an ID5o__<5mg/kg.
In an alternative method, the NK-1 receptor antagonist is
administered orally, 4 hours prior to isolation, wherein vocalisations
during the first 15 minutes of isolation are attenuated with an
IDso520mg/kg, preferably with an IDso__<lOmg/kg, and especially with an
IDso<5mg/kg.
A suitable selection cascade for NKl antagonists of use according to
the present invention is as follows:
(i) Determine affinity for human NKl receptor in radioligand
binding studies (Assay 1); select compounds with ICso < lOnM, preferably
ICso <_ 2nM, especially ICso < lnM.
(ii) Determine ability of compounds to penetrate CNS by their
ability to inhibit foot tapping in gerbils induced by central injection of an
NKl agonist (Assay 2); select compounds that inhibit foot tapping with
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38
ID~o < 3mg/kg i.v., and preferably IDso < lmg/kg i.v. when administered
immediately prior to central NKl agonist challenge, or IDso < 30mg/kg p.o.,
and prefer ably IDso _< lOmglkg p.o. 1 hour prior to challenge.
{iii) Determine central duration of action of compounds in gerbil foot
tapping assay following intravenous administration 24 hours prior to
central NKi agonist challenge; select compounds showing 5 25-fold loss of
potency compared with IDso determined in step (ii) above with the proviso
that IDso < lOmg/kg i.v.) and preferably 5 5mg/kg i.v. after 24 hour
pre-tr eatment. .
(iv) Determine oral bioavailability of compounds by
pharmacokinetic analysis, activity in gerbil foot tapping assay following
oral administr ation andlor by ability to inhibit cisplatin-induced emesis in
ferrets (Assay 3); select compounds with IDso s 3mg/kg p.o., and preferably
IDoo S lmg/kg p.o.
Particularly preferred compounds of use in the present invention
are- identified using- steps (i) to (iv) followed by step (v):
(v) Determine activity of compounds in assays sensitive to
conventional antipsychotic drugs (inhibition of distress vocalisations in
guinea-pig pups (Assay 4)). Select compounds with IDso _< 20mg/kg, and
preferably ID~o <_ lOmg/kg.
Yet further preferred compounds of use in the present
invention may be selected from those compounds which satisfy the NK-1
receptor binding criteria of step (i) which, in addition, have S 5-fold shift
in
affinity when incubated in the presence of human serum albumin (HSA) to
show non-specific protein binding.
One example of a NK-1 receptor antagonist of use in the present
invention is the compound 2-(R)-(1-(R)-(3,5-bis(trifluoromethyl)phenyl)-
ethoxy)-3-(S)-(4-fluorophenyl)-4-(3-(5-oxo- IH, 4H-1, 2, 4-triazolo)methyl)-
morpholine) the prepay ation of which is described in International Patent
Specification No. WO 95116679. In the aforementioned assays, this
compound has the following activity:
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human NK-1 receptor binding: ICso=O.lnM
gerbil foot-tapping (5 mins.): ID,o=0.36mg/kg i.v.
gerbil foot-tapping (24 hrs.): IDso=0.33mg/kg i.v.
ferret emesis: IDoo<3mg/kg p.o.
guinea-pig vocalisation
(4 hr. pre-treatment): ID5o=0.73mg/kg p.o.
The following example illustrates pharmaceutical compositions
according to the invention.
EXAMPLE 1 Tablets containine 50-300m~ of NK-1 antagonist
Amount m~
NK-1 antagonist 50.0 100.0 300.0
Microcrystalline cellulose 80.0 80.0 80.0
Modified food corn starch 80.0 80.0 80.0
Lactose 189.5 139.5 139.5
Magnesium Stearate 0.5 0.5 0.5
The active ingredient, cellulose, lactose and a portion of the corn
starch are mixed and granulated with 10% corn starch paste. The
resulting granulation is sieved, dried and blended with the remainder of
the corn starch and the magnesium stearate. The resulting granulation is
then compressed into tablets containing 50mg, 100mg and 300mg of the
NK-1 receptor antagonist per tablet.
